<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .list{
            height: 100px;
        }
        li{
            width: 300px;
            height: 100px;
            float: left;
        }
        .clear{
            clear: both;
        }
        li:nth-child(1){
            background-color: aqua;
        }
        li:nth-child(2){
            background-color: red;
        }
        li:nth-child(3){
            background-color: green;
        }
    </style>
</head>
<body>

    <ul class="list">
        <li>1</li>
        <li>2</li>
        <li>3</li>
        <!-- <div class="clear"></div> -->
    </ul>

    <h2 class="title">hello</h2>

</body>
</html>